Reports: B10
47900-B10 Porphyrin Nanostructures as Light Harvesting Antennas for Dye-Sensitized Solar Cells
During the reporting period, four undergraduate students and I studied porphyrin nanostructures that could potentially be used as light harvesting antennas in dye-sensitized solar cells. We investigated self-assembly of meso-tetra(4-sulfonatophenyl)porphine (TPPS4) in aqueous solutions and found that well-defined TPPS4 J-aggregates could be formed on polypeptide templates when TPPS4.sulfonate groups bind to cationic lysine amino acid residues. We characterized such peptide : porphyrin complexes using absorption, fluorescence, light scattering, and CD spectroscopy. We also found that the secondary structure of the peptide (transition from random to a-helical conformation) could be changed due to porphyrin binding to the peptide. Our results are reported in a manuscript submitted to J. Phys. Chem. B: Kuciauskas and Caputo, Self-assembly of peptide-porphyrin complexes leads to pH-dependent excitonic coupling. Undergraduate students participating in the project presented three posters at Rowan’s annual STEM symposium. We have also made a presentation at the IUPAC Congress, Symposium on Artificial Photosynthesis (August 2009, Glasgow, UK). In addition, we started projects on: a) binding of anionic porphyrins to nanostructured semiconductor surfaces, b) excited state dynamics of peptide : porphyrin antennas, and c) characterization of photovoltage-photocurrent characteristics of solar cells.
